Radiocoupler



July 6,1926. 1,591,552

Lv W. ENGELHART RADIOCOUPLER Filed Oct. 2, 1924 Patented July 6, 1926.

LIWRENCEWILLIAM 'ENGE IJHART', OFSTKPLETON, NEW YORK.

RADIGCOUPLER.

Application filed Octbber 2, 19%. Serial an. arms;

The present invention relates to radio telephony :and: has for an object to provide an improved coupler arrangement therefor. The 1eflioiency of radio apparatus and particularly certain. couplers of radio receiving sets; can be materially increased by reducing the distributed capacity of the coils thereof. The presence of magnetic orany metal inor :closely adjacent to the l coials obviously has. a. considerable effect and If the bare wire coils could be supported in such a manner as to be entirely surrounded by l air actingv as. aniinsuilator and dielectrio mnchbetter results would be obtained than in the present commercial apparatus. 'Ilhe present :a-pparatus isxdesigned to provide an arrangement whereby this theoretical condition is approached as nearly as feasible.

The natureand objects of the invention will be better understood from a description of a particular illustrative apparatus constructed in accordance with and embodying the purpose of the invention. For the purposes of such description, reference should be had to the accompanying drawing forming a part hereof and in which,

Figure 1 is a view in end elevation of a radio coupler designed more particularly for a receiving set.

Figure 2 is a plan view of the same.

Figure 3 is a detailed view of the wire indicating the double cotton wrapping.

The apparatus shown for the purposes of illustration comprises a primary C01l 5, arranged to be connected to the antenna, a secondary coil 6 and a tickler coil 7 all arranged to be connected as usual in, for example, the Armstrong regenerative receiving circuit. In order to reduce the capacity of the coils as much as possible each coil is supported by means positioned exteriorly thereof and spaced ata substantial distance therefrom, the coil being suspended in'a rclatively rigid. manner as by means of suitable tapes such as the cotton tapes indicated at 9, Fig; 2. As shown, the support for the primary =coil liconsists. of a single annular support lO'which is preferably made of non-- magnetic insulating material such for example as bakelite or hard rubber. This annular support is preferably positioned about. midway of the length of the coil in order thatlit may lie in asweak a ;1JOI'tl0I1 o t' the magnetic field as possible and therefore have as little effect as possible upon. the capacity and inductance of tlie coirl. 'Ehis annular support is preferably:supported for angular adjustment as shown and as hereinafter described.

The coil itself in the illustrative embodiment consists of a Wire having a double cotton covering. This wire being bent to a form such that each turn of the coil repeatedly crosses the next adjacent turn of the 'coilwin such manner that the successive turns, by bearingagainst each other may be formed into a'ielatively rigid whole. The coil of the structure particularly illustrated may be formed by winding a double'cotton covered wire aboutsinteen pins positioned in a circle, the wire being passed outside of one pin, inside of the neat two. outside of the. next one, etc., until the coil iscomplete l y' formed. By this construction each :turn of the coil crosses iand 'bears against eachadjacent coil in eleven places and if a relatively rigid wire is used, the coil as a whole constitutes a relatively rigid structure. This rigidity may be increased by binding the several turns of the coil together by means of cotton tape or other suitable binding means. The coil thus formed is mounted within the annular support and is suspended from four points thereof by means of thin cotton tapes 9.

The wire used is preferably soft and without spring so that it retains its shape when bent. Obviously, if the wire used is sufliciently rigid the several turns of the coil may be slightly spaced from each other so as not to come in contact. However, the construe tion first described is ordinarily preferable for mechanical reasons.

The secondary coil 6 is similar to the pri mary coil 5 except that it is substantially longer and larger and for this reason preferably two supporting.members 14: and 15 are provided, the coil being suspended from these members by means of suitable tapes as heretofore described in connection with the coil 5. The supports 14- and 15 furthermore carry horizontal rods 16 and 17 on opposite sides thereof which rods serve as supports for the tickler coil carrying frame and for the primary coil carrying frame.

The tiekler coil 7 is similar in construction to the primary and secondary coils. It and the primary coil may be, as shown, of smaller diameter than the secondary coil and both may be made of smaller wire. llhese features are controlled by electrical requirements. As shown, the tickler coil is supported in a rotatable, annular frame 18 being tied therein by means of suitable tapes 19. The adjustable, rotatable frame 18 is mounted in bearings carried by the ends of the rods 16 and 'l'? and may be rotatably adjusted therein to vary the regencrative effect as desired. As shown, the fielder coil is co nected to the circuit by means of flexible leads at opposite sides thereof. These flexible leads permit adjustment of the coil while still maintaining the circuit.

Preferably friction means is provided for holding the tickler coil in adjusted position. As shown, springs 20 and 21 are arranged between collars on the frame trunnions and the supporting members 16 and 17 provide sull icicnt friction for maintaining the frame in adjusted position. One of the trunnions is extended from the supporting frame to provide a handle 22 for convenience in adjustment.

The mounting of the primary coil preferably provides for angular adjustment as heretofore suggested. It may conveniently be mounted in the ends of the rods 16 and 17 in the same manner that the tickler coil is mounted in the opposite ends thereof;

The annular supports of the secondary coil constitute standards and are preferably formed with laterally extending feet arranged to be suitably secured to the supporting table on which the coils are to be atiixed.

The rigidity of the support for the secondary coil may be and preferably is increased by providing bracing rods 23 and 24 secured in both these supports at the top and bottom thereof to hold them in definite spaced relation.

The description of the particular ar rangcment shown is illustrative merely and is not intended as defining the limits of the invention,

I claim:

1. A radio coupler comprising, a wire formed to provide a relatively rigid self sustaining coil and an annular support midway of the length thereof and spaced ther from, and means securing the coil to the support.

2. A radio coupler comprising a self sustaining coil, and an annular sup ort surrounding the same and spaced t erefrom midway of its length together with means securing the coil in place in the annular support.

3. In radio apparatus a self-sustaining (coil and a support substantially surrounding the same and spaced therefrom midway of its length flexible non-metallic tension members securing the coil centrally in the support.

4. In radio apparatus a self-sustaining coil and a support midway of its length extending to opposite sides thereof together witlrflexible non-metallic tension members securing the coil centrally in said support.

In testimony whereof, I have signed my name to this specification this 29th day of September 1924f.

'LAlVRENCE VILLTAM ENGELHART. 

